1 //===------ OrcLazyJIT.cpp - Basic Orc-based JIT for lazy execution -------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "OrcLazyJIT.h"
11 #include "llvm/ExecutionEngine/Orc/OrcTargetSupport.h"
12 #include "llvm/Support/Debug.h"
13 #include "llvm/Support/DynamicLibrary.h"
14 #include <cstdio>
15 #include <system_error>
16 
17 using namespace llvm;
18 
19 namespace {
20 
21   enum class DumpKind { NoDump, DumpFuncsToStdOut, DumpModsToStdErr,
22                         DumpModsToDisk };
23 
24   cl::opt<DumpKind> OrcDumpKind("orc-lazy-debug",
25                                 cl::desc("Debug dumping for the orc-lazy JIT."),
26                                 cl::init(DumpKind::NoDump),
27                                 cl::values(
28                                   clEnumValN(DumpKind::NoDump, "no-dump",
29                                              "Don't dump anything."),
30                                   clEnumValN(DumpKind::DumpFuncsToStdOut,
31                                              "funcs-to-stdout",
32                                              "Dump function names to stdout."),
33                                   clEnumValN(DumpKind::DumpModsToStdErr,
34                                              "mods-to-stderr",
35                                              "Dump modules to stderr."),
36                                   clEnumValN(DumpKind::DumpModsToDisk,
37                                              "mods-to-disk",
38                                              "Dump modules to the current "
39                                              "working directory. (WARNING: "
40                                              "will overwrite existing files)."),
41                                   clEnumValEnd),
42                                 cl::Hidden);
43 
44   cl::opt<bool> OrcInlineStubs("orc-lazy-inline-stubs",
45                                cl::desc("Try to inline stubs"),
46                                cl::init(true), cl::Hidden);
47 }
48 
49 std::unique_ptr<OrcLazyJIT::CompileCallbackMgr>
createCompileCallbackMgr(Triple T)50 OrcLazyJIT::createCompileCallbackMgr(Triple T) {
51   switch (T.getArch()) {
52     default: return nullptr;
53 
54     case Triple::x86_64: {
55       typedef orc::LocalJITCompileCallbackManager<orc::OrcX86_64> CCMgrT;
56       return llvm::make_unique<CCMgrT>(0);
57     }
58   }
59 }
60 
61 OrcLazyJIT::IndirectStubsManagerBuilder
createIndirectStubsMgrBuilder(Triple T)62 OrcLazyJIT::createIndirectStubsMgrBuilder(Triple T) {
63   switch (T.getArch()) {
64     default: return nullptr;
65 
66     case Triple::x86_64:
67       return [](){
68         return llvm::make_unique<
69                        orc::LocalIndirectStubsManager<orc::OrcX86_64>>();
70       };
71   }
72 }
73 
createDebugDumper()74 OrcLazyJIT::TransformFtor OrcLazyJIT::createDebugDumper() {
75 
76   switch (OrcDumpKind) {
77   case DumpKind::NoDump:
78     return [](std::unique_ptr<Module> M) { return M; };
79 
80   case DumpKind::DumpFuncsToStdOut:
81     return [](std::unique_ptr<Module> M) {
82       printf("[ ");
83 
84       for (const auto &F : *M) {
85         if (F.isDeclaration())
86           continue;
87 
88         if (F.hasName()) {
89           std::string Name(F.getName());
90           printf("%s ", Name.c_str());
91         } else
92           printf("<anon> ");
93       }
94 
95       printf("]\n");
96       return M;
97     };
98 
99   case DumpKind::DumpModsToStdErr:
100     return [](std::unique_ptr<Module> M) {
101              dbgs() << "----- Module Start -----\n" << *M
102                     << "----- Module End -----\n";
103 
104              return M;
105            };
106 
107   case DumpKind::DumpModsToDisk:
108     return [](std::unique_ptr<Module> M) {
109              std::error_code EC;
110              raw_fd_ostream Out(M->getModuleIdentifier() + ".ll", EC,
111                                 sys::fs::F_Text);
112              if (EC) {
113                errs() << "Couldn't open " << M->getModuleIdentifier()
114                       << " for dumping.\nError:" << EC.message() << "\n";
115                exit(1);
116              }
117              Out << *M;
118              return M;
119            };
120   }
121   llvm_unreachable("Unknown DumpKind");
122 }
123 
124 // Defined in lli.cpp.
125 CodeGenOpt::Level getOptLevel();
126 
127 
128 template <typename PtrTy>
fromTargetAddress(orc::TargetAddress Addr)129 static PtrTy fromTargetAddress(orc::TargetAddress Addr) {
130   return reinterpret_cast<PtrTy>(static_cast<uintptr_t>(Addr));
131 }
132 
runOrcLazyJIT(std::unique_ptr<Module> M,int ArgC,char * ArgV[])133 int llvm::runOrcLazyJIT(std::unique_ptr<Module> M, int ArgC, char* ArgV[]) {
134   // Add the program's symbols into the JIT's search space.
135   if (sys::DynamicLibrary::LoadLibraryPermanently(nullptr)) {
136     errs() << "Error loading program symbols.\n";
137     return 1;
138   }
139 
140   // Grab a target machine and try to build a factory function for the
141   // target-specific Orc callback manager.
142   EngineBuilder EB;
143   EB.setOptLevel(getOptLevel());
144   auto TM = std::unique_ptr<TargetMachine>(EB.selectTarget());
145   auto CompileCallbackMgr =
146     OrcLazyJIT::createCompileCallbackMgr(Triple(TM->getTargetTriple()));
147 
148   // If we couldn't build the factory function then there must not be a callback
149   // manager for this target. Bail out.
150   if (!CompileCallbackMgr) {
151     errs() << "No callback manager available for target '"
152            << TM->getTargetTriple().str() << "'.\n";
153     return 1;
154   }
155 
156   auto IndirectStubsMgrBuilder =
157     OrcLazyJIT::createIndirectStubsMgrBuilder(Triple(TM->getTargetTriple()));
158 
159   // If we couldn't build a stubs-manager-builder for this target then bail out.
160   if (!IndirectStubsMgrBuilder) {
161     errs() << "No indirect stubs manager available for target '"
162            << TM->getTargetTriple().str() << "'.\n";
163     return 1;
164   }
165 
166   // Everything looks good. Build the JIT.
167   OrcLazyJIT J(std::move(TM), std::move(CompileCallbackMgr),
168                std::move(IndirectStubsMgrBuilder),
169                OrcInlineStubs);
170 
171   // Add the module, look up main and run it.
172   auto MainHandle = J.addModule(std::move(M));
173   auto MainSym = J.findSymbolIn(MainHandle, "main");
174 
175   if (!MainSym) {
176     errs() << "Could not find main function.\n";
177     return 1;
178   }
179 
180   typedef int (*MainFnPtr)(int, char*[]);
181   auto Main = fromTargetAddress<MainFnPtr>(MainSym.getAddress());
182   return Main(ArgC, ArgV);
183 }
184